How to choose a projection blending solution?

Projection blending technology is designed to achieve image stitching from multiple projectors to achieve ultra-large size, ultra-high resolution, and seamless warping & blending. Its key technologies include geometry warping and edge blending. It is widely used in exhibitions, virtual simulations, immersive theaters and other scenarios, and plays a significant role in the three major display industries (LCD, LED, and projection).

With the development of the times and the progress of the industry, the technology of projection blending is also developing day by day; at the same time, with the increase in users, each user has their own specific effects that need to be achieved. In order to meet the needs of more users, projection blending technology has also become diverse.

When it comes to projection blending solutions, some people say it is done with software, some say it is done with hardware, some say it is only achieved with a graphics card, and some say my projector has a built-in blending function...

I believe that many people are confused after reading this. With so many opinions, how are projection blending technologies classified? What are their respective advantages and disadvantages? How should one choose? Next, we will guide you in answering these questions. I believe that after reading this article, your understanding of projection blending solutions will be clear at a glance!

Based on the different processing devices used, it is usually divided into the following three categories: software projection blending, hardware projection blending, and embedded projection blending. Each has its own advantages, and different technologies are selected for different scenarios.

 

1.Software projection blending

Principle: Rely on the computer CPU or GPU to run dedicated blending software to process the geometric warping and edge blending of the overlapping areas of the projection in real time.

Presentation form: PC + blending software + multi-screen expander + projector

Applicable scenarios: scenarios with limited budget and low requirements for real-time performance and synchronization, or scenarios with dome or bowl-shaped screens.

Advantages:

• Moderate cost. No special hardware equipment is required, only a projector and a PC are needed. If there are many projectors, you can add a multi-screen expander to expand channels. If the requirements are not high, you can choose more cost-effective blending software.
• High flexibility. Supports multiple screen forms such as flat, curved, bowl, or dome screens. Ordinary blending software generally does not support bowl or dome screens, so you need to choose blending software according to your specific needs.

Shortcomings:

• Performance is limited. The display may lag at high resolutions, occupy a lot of CPU resources, and affect the operation of other programs.
• Poor compatibility. Mostly limited to specific file formats (such as video or VR content), with weak real-time signal processing capabilities.

 

2. Hardware projection blending

Principle: Use dedicated hardware devices (such as FPGA-based blending processors) to independently process signals to achieve geometric warping, color correction, and edge blending.

Form of expression: PC + hardware blending device + projector

Applicable scenarios: large control rooms, monitoring centers, and other scenarios that require high reliability and multi-signal access.

Advantages:

• Strong compatibility. Supports multi-channel signal input and real-time processing without delay.
• High stability. Pure hardware architecture, no risk of system crash, supports 24/7 operation.

Shortcomings:

• Higher cost. Dedicated blending devices are more expensive (especially plug-in card devices or those that support high resolution).
• Low flexibility. Surface correction capabilities are limited. For example, scenarios such as bowl or dome screens are not as convenient as with software blending.

 

3.Embedded projection blending

Principle: Through dedicated embedded (such as Android, Linux, or Kirin systems) hardware devices (based on SoC fusion processors such as Rockchip and HiSilicon), it integrates playback, splicing, and blending to achieve functions such as geometric warping, color correction, edge blending, and video playback.

Display form: embedded blending device + projector

Applicable scenarios: small and medium-sized integrated fixed-installation projects (such as corporate exhibition halls) that prioritize system simplicity.

Advantages:

• Low cost. One device replaces the computer, splicer, and blending software, featuring high integration and lower overall costs.
• System simplification. No external blending device or input source is required, which reduces transmission links and minimizes latency.
• High flexibility. Can be applied to various bowl, dome, and curved surfaces (depending on specific software support).

Shortcomings:

• Asynchronous playback. Internal decoding playback; if an external signal is needed, it can only be played through signal acquisition.
• Performance is limited. Different products have different decoding capabilities, and the display is prone to lag at high resolutions and high refresh rates.

Simply put, if you have high requirements and a sufficient budget, choose hardware projection blending; if the budget and requirements are moderate, choose software blending; if the budget is low and the input source does not change frequently, you can consider embedded projection blending.

The above is purely my personal opinion. If you have different views, you are welcome to discuss them. If you have project requirements, feel free to consult with us, and we will recommend the best solution for you!

niber.wen@bitvisus.com